Bone tamp apparatus and method

ABSTRACT

A tamping apparatus is described that includes a cannula that has a tubular wall that includes a distal end portion that defines a tamping face. The cannula defines a longitudinally aligned aperture or lumen that provides access for an insert and the injection of treatment materials such as a bone graft. The distal end portion of the cannula can also include a plurality of movable elements that can be a part of or connected to the tubular wall. The tamp apparatus can also include a cannula or stylet that can be moved within aperture of cannula and is employed to move elements between the first position and second position of tamp apparatus.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to provisional patent application60/836,011 filed Aug. 7,2006, the disclosure of which is incorporated byreference herein in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to surgical tamps and more specifically toa bone tamp apparatus.

2. Description of the Related Art

Bone tamps provide surgeons a valuable option for the repair ofcompression bone fractures. The tibial plateau, as one example, isvulnerable to being fractured and depressed due to varus or valgusstress and/or axial compression. Bone tamps are used to reposition thefractured and displaced bone into a natural position. Prior art bonetamps are typically simple solid straight instruments that have acylindrical shape and a distal face or tamping surface with a fixedquantity of surface area for the displacing of bone tissue. The tampingsurfaces of prior art bone tamps are solid and have flat disk typeshapes without openings or breaks in the tamping surfaces.

In one current surgical procedure as an example, access to the tibia iscreated by making a surgical incision in a generally anterior and medialposition on the proximal aspect of the tibia, below the level of thetibial plateau fracture as shown in FIG. 1 (prior art). An opening isthen created in the hard, outer, cortical bone in line with thisincision in order to provide access for a bone tamp. This opening in thecortical bone is typically created by making multiple drill holes in acircular shape and then connecting these holes through the use of anosteotome and a mallet. After removing this “cortical window” in thebone, a tamp is inserted through the window into the soft, innercancellous bone where it is then positioned for treating the tibiafracture. A mallet is used to tap the proximal terminal end and drivethe distal tamping face of the tamp into the fracture. The tamprepositions the displaced bone material into a natural position.

When the tamping of the displaced bone material is completed, the tampis withdrawn. The path taken by tamp to return the displaced bone to thenatural position leaves a void in the bone that is then backfilled usinga bone graft or bone graft substitute such as various, commerciallyavailable bone cements. The back filling procedure places the bone graftinto the void by injecting the material through a large bore needle orcannula. Tamps may also be used to compress the backfilled bone graft toensure the structural integrity of the graft. The term bone graft asdefined herein includes a bone graft, bone graft substitute, bone cementor any another material approved for use as a bone graft. The termtamping surface as defined herein is the distal terminal end or face ofthe tamp that directly contacts the cancellous bone as described aboveto displace that bone and/or compress the bone graft.

The simple prior art bone tamp is limited in its ability to performadditional functions during a surgical procedure. For example, the tamprequires a large bone window and skin incision. This causes significantbleeding and soft tissue trauma. The placement of the tamp directlybelow the fracture site can also be difficult and typically requiresseveral trial and error attempts each of which leaves a path of bonevoid which needs to be backfilled at the end of the procedure. Theapplication of the prior art tamp to many common fractures can alsorequire an excessive amount of time due to the relatively small surfaceof the face of the tamp relative to the wider surface of the fracture.Effective backfilling can also be compromised by the fact that the priorart tamps require a two step process in which the tamp is removed andthen the bone graft is injected into the void. Problems occur becauseupon the removal of the tamp from the bone, blood begins to accumulatein the void from the tamp that prevents an optimal graft integrationwith the native bone.

While cannulas have expandable structures for different functions, suchas those in U.S. Pat. No. 6,632,197 to Lyon that, is incorporated hereinby reference and made a part of this disclosure, heretofore bone tampshave neither had apertures aligned with the longitudinal axis orstructures that increase the tamping surface area. Tamps have not hadapertures for receiving a guide wire which can perform functions such asthe scouting out and aligning of the ultimate trajectory of the tamp aswelt as the introduction of backfill.

The repair of certain bone fractures, such as those of the tibialplateau can benefit from a tamp apparatus that is not solely limited totamping. A tamp apparatus is needed that combines a tamp and a cannulathat defines a through hole or aperture that is aligned with alongitudinal axis of the tamp. The aperture advantageously provides apassageway for a guide wire such that the tamp apparatus can be slidover an accurately pre-positioned guide wire that is placed beneath thedepressed fragment of bone. The guide wire can then be used to directthe tamp to the desired point and angle for application. In addition,the aperture allows for the subsequent injection of bone graft throughthe aperture of the cannula as the tamp is withdrawn from the fracturesite. Further, a tamp apparatus is needed that has a narrowcross-section that can be selectively expanded to increase the tampingsurface.

SUMMARY OF THE INVENTION

A tamp apparatus is described for use in surgical operations thatcomprises a cannula that has a tubular wall that has a distal endportion and a proximal end portion. The distal end portion includes adistal terminal end and the proximal end portion includes a proximalterminal end. The tubular wall of the cannula defines an aperture. Theaperture extends from a first opening defined in the proximal terminalend to a second opening defined in the distal terminal end. A tampingsurface for displacing bone is defined by the distal terminal end of thedistal end portion of cannula between an outside diameter of the tubularwall of distal terminal end and an outside diameter of the secondopening. The first opening has a first diameter and the second openinghas a second diameter such that the diameter of the first opening islarger than the diameter of the second opening. The distal end portionand proximal end portion of the cannula define a central longitudinalaxis.

The distal end portion includes a plurality of slots defined in thetubular wall and the slots define a plurality of elements. The elementsare movable between a first position aligned with the longitudinal axisand a second position oblique to the longitudinal axis. The elements arecantilevered portions of the tubular wall that reduce the diameter ofthe second opening of the aperture in the first position of the tampapparatus. The elements have terminal ends that define a tamping face ofthe cannula. The elements include at least one hinge. A displacing forcerotates the elements about their respective hinges from the firstposition aligned with the longitudinal axis to the second positionoblique to the longitudinal axis. The elements include a retentionmechanism or elasticity that biases the elements to the first position.

The tamp apparatus can further includes a stylet and the stylet has atubular wall that includes a distal end portion, a central section and aproximal end portion. The distal end portion includes a distal terminalend and the proximal end portion includes a proximal terminal end. Anaperture is defined by the tubular wall of the stylet. The apertureextends from a first opening defined in the proximal terminal end to asecond opening defined in the distal terminal end. At least the tubularwail of the distal end portion and the central section of the stylet arepositionable in the aperture of the cannula. The cannula and the styletare connectable together into an integrated assembly.

A surgical tamp is described that comprises a tamp apparatus. The tampapparatus includes a cannula. The cannula has a tubular wall that has adistal end portion and a proximal end portion. The distal end portionhas a distal terminal end and the proximal end portion has a proximalterminal end. An aperture is defined by the tubular wail of the cannulathat extends from a first opening defined in the proximal terminal endto a second opening defined in the distal terminal end. A first positionof the tamp apparatus defines a first tamping surface area and a secondposition of the tamp apparatus defines a second tamping surface area.The second tamping surface area has a greater tamping surface area thanthe first tamping surface area.

The surgical tamp can further include an insert. The insert has aproximal end portion and a distal end portion. The insert ispositionable in the aperture of the cannula. The distal end portion ofthe insert includes a tamping face that increases the tamping surfacearea of the tamp apparatus in the second position. The cannula caninclude a plurality of movable elements that have tamping faces. Theelements are approximately aligned with the aperture in the firstposition and in the second position the tamping faces deploy to increasethe tamping surface area of the tamp apparatus. The surgical tamp canfurther include at least one stylet that has a tamping face. The styletis positionable in the aperture and the stylet deploys the tamping facesof the elements from the first position to the second position. Thetamping face of the stylet and the tamping faces of the elementsincrease the tamping surface area of the tamp apparatus in the secondposition.

A method of treating a bone fracture using a tamp apparatus comprisingthe steps of introducing a guide wire through a pre-existing incision ina cortex of a bone and positioning a distal end of the guide wire inproximity to a bone fracture. Coupling a longitudinally aligned lumen ofthe tamp apparatus to the guide wire and positioning a distally directedtamping face of the tamping apparatus for treating the fracture.Treating the fracture using the tamping fate to displace the fracturedbone material to an approximately natural position.

The method can further comprise removing the guide wire from the tampapparatus when the tamp apparatus is positioned for treating thefracture. The method can also further comprise selectively positioningthe tamp apparatus between a first position with a first tamping facesurface area and a second position with a second tamping face surfacearea. The second tamping face surface area is greater than the firsttamping face surface area. The method further comprising injecting bonegraft material through a distal opening of the lumen of the tampapparatus to further treat the displaced fractured bone.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention are described below withreference to the drawings, wherein like numerals are used to refer tothe same or similar elements.

FIG. 1 is a side perspective view of a tibial plateau fracture beingtreated with a prior art tamp;

FIG. 2 is a side and rear perspective view of one preferred embodimentof a bone tamp apparatus that includes a cannula, a guide wire and aninsert constructed in accordance with the present disclosure;

FIG. 3 is a side and front perspective view of the bone tamp apparatusand guide wire of FIG. 2 with the guide wire positioned through anaperture in a cannula of the tamp apparatus;

FIG. 4 is a side view of a second embodiment of the tamp apparatus ofFIG. 2 in a first position, the tamp apparatus includes a stylet and acannula constructed in accordance with the present disclosure;

FIG. 5 is a side cross-sectional view of the cannula of FIG. 4 takenalong lines 5-5.

FIG. 6 is a front perspective view of a distal end portion of thecannula of FIG. 4 that has one of the four elements removed;

FIG. 7 is a side cross-sectional view of the stylet of the tampapparatus of FIG. 4 taken along lines 7-7;

FIG. 8 is a front and side perspective view of a distal end portion of asecond embodiment of the stylet of FIG. 4 wherein the distal end portionhas a taper that increases the diameter of a terminal end of the stylet;

FIG. 9 is a close up of the side cross-sectional view of the stylet ofFIG. 8 positioned in the aperture and in direct contact with theelements of the cannula of FIG. 5;

FIG. 10 is a side cross-sectional view of the cannula and stylet of FIG.4 in a second position of the tamp apparatus;

FIG. 11 is a perspective view of the distal end portions of the cannulaand stylet of the tamp apparatus of FIG. 4 in a second position with thestylet and expanded elements defining an expanded tamping surface;

FIG. 12 is a side cross-sectional view of the distal end portions of thecannula and stylet of FIG. 11 taken along lines 12-12;

FIG. 13 is a side and front perspective view of a third embodiment oftamp apparatus of FIG. 2 in a first position that includes a pluralityof hinged elements.

FIG. 14 is a cross-sectional view of the tamp apparatus of FIG. 13 alonglines 14-14.

FIG. 15 is a side and front perspective view of a third embodiment oftamp apparatus of FIG. 2 in a second position that includes a pluralityof hinged elements pivoted to define an increased tamping surface.

FIG. 16 is a cross-sectional view of the tamp apparatus of FIG. 15 alonglines 16-16.

FIG. 17 is a front view of a distal end of the tamp apparatus of FIG.15.

FIG. 18 is a side and front perspective view of a fourth embodiment ofthe tamp apparatus of FIG. 2 in a first position that includes multiplehinges for the movement of the elements constructed in accordance withthe present disclosure;

FIG. 19 is a cross-sectional view of the tamp apparatus of FIG. 18 alonglines 19-19;

FIG. 20 is a front perspective view of the tamp apparatus of FIG. 18 ina second position that shows the elements rotated to form a tampingsurface;

FIG. 21 is a side cross-sectional view of the tamp apparatus of FIG. 20along lines 21-21 in the second position that shows the elements flexedto a second position;

FIG. 22 is a simplified side view of a distal end of the guide wire ofFIG. 2 being inserted through a surgical incision and being positionedin proximity to the tibial plateau fracture;

FIG. 23 is a simplified side view of the tamp apparatus of FIG. 2 beinginserted through the surgical incision and being guided towards thetibial plateau fracture by the guide wire;

FIG. 24 is a simplified side view of the tamp apparatus of FIG. 2 beingaligned for displacing a tibial plateau fracture;

FIG. 25 is a simplified side view of the tamp apparatus of FIG. 2injecting bone graft into the void created by the bone tamp as the bonetamp is withdrawn from the tibia;

FIG. 26 is a simplified side view of the tamp apparatus of FIG. 4 in asecond position positioned in a tibia, the cannula and stylet connectedand the elements deployed to define an increased tamping surface;

FIG. 27 is a simplified side view of the tamp apparatus of FIG. 13 in afirst position that includes the cannula and a first stylet beinginserted into a tibia;

FIG. 28 is a simplified side view of the tamp apparatus of FIG. 13 in asecond position that includes the cannula and a second stylet positionedin the tibia, the elements deployed to define an increased tampingsurface; and

FIG. 29 is a simplified side view of the tamp apparatus of FIG. 18 insecond position in a tibia with the elements deployed to define anincreased tamping surface.

DETAILED DESCRIPTION OF THE INVENTION

Referring to the drawings and initially to FIG. 1, a prior art tamp 5 isshown that is a simple solid straight cylindrically shaped rod. Tamp 5is provided with access to the vicinity of an anterior portion of thetibial plateau by a surgical incision. A distal terminal end 6 of tamp 5is positioned on the tibia and a proximal terminal end 7 of tamp 5 isstruck to displace the compressed bone structure. Once the depressedportion of the tibial plateau has been elevated to approximate theoriginal tibial plateau surface, tamp 5 is withdrawn. A separate device,such as a stylet or syringe (not shown) is then positioned into theincision to supply a bone graft or another material such as a bone graftsubstitute or cement to fill the displaced bone of the tibia. Tamp 5 isthen used to compress the backfilled bone graft.

As shown in FIG. 2, tamp apparatus 10 in this preferred embodiment is acylindrical shaped tubular cannula 12 that includes a central section14, a distal end portion 16 and a proximal end portion 18. Cannula 12defines a central longitudinal axis-X between distal end portion 16 andproximal end portion 18. Distal end portion 16 has a terminal end ortamping face 17. Proximal end portion 18 has a terminal end or base 19.Cannula 12 is shown as having a straight shape, but it is understoodthat cannula 12 can also have an arcuate shape. Tamp apparatus 10 canselectively include an insert 9 and/or a guide wire 11.

Proximal end portion 18 preferably has a larger diameter than tubularwall 22 of central section 14 and distal end portion 16. The largerdiameter of proximal end portion 18 provides a larger proximallydirected surface of base 19 that provides a larger target or strikingarea. Base 19 has a flat surface that is suitable for being tapped orstruck by a mallet, for example.

Insert 9 is a solid cylindrical stylet that has a center section thatconnects a proximal end portion 9A and a distal end portion 9B. Proximalend portion 9A preferably connects to proximal end portion 18 of cannula12 to form a single integrated assembly that transfers a force appliedto cannula 12 and/or insert 9 along the longitudinal axis. Distal endportion 9B includes a distally directed terminal end or tamping facethat combines with the tamping face 17 of cannula 12 to increase thetamping surface of tamp apparatus 10.

Guide wire 11 has a distal end 13 and a proximal end 15. In thispreferred embodiment, guide wire 11 is preferably a straightsubstantially rigid cylindrically shaped wire, but it is understood thatguide wire 11 can have alternate shapes, such as arcuate, or be at leastpartially flexible.

Referring now to FIGS. 2 and 3, cannula 12 has a tubular wall 22 thatdefines an aperture 23 that is aligned with the longitudinal axis-X. Inthis preferred embodiment, cannula 12 is a fluid tight conduit or lumenthat extends between a first opening 24 in base 19 and a second opening25 defined in face 17. Aperture 23 has a diameter that is at leastslightly larger than the diameter of guide wire 11.

In this preferred embodiment, base 19 defines a recessed or hollowed outarea that has a recessed surface below or distal to base 19. Therecessed surface defines first opening 24 that can include a standardinterface such as a leur lock, for example, that can connect with asyringe or another surgical instrument.

Second opening 25 of aperture 23 has a diameter that is preferably lessthan a diameter of first opening 24. The relatively small and/ordecreased diameter of aperture 23 at, second opening 25 advantageouslyincreases the tamping surface of face 17. The diameter of second opening25 is at least sufficient to define a passageway for guide wire 11and/or the injection of bone material.

Insert 9 is removably positionable into aperture 23 through firstopening 24. When insert 9 is fully positioned into aperture 23, tampapparatus 10 is in a second position wherein distal end portion 9Btamping face defines an additional portion of the tamping surface oftamp apparatus 10 in combination with tamping face 17. Insert 9 canselectively provide a close fitting relationship and/or sealinginterface with tamping face 17 and/or aperture 25. Insert 9 is shown asa solid cylindrical shall, but it is understood that insert 9 could havea variety of shapes depending upon the intended application.

Guide wire 11 can be inserted into aperture 23 and rotated about thelongitudinal axis-X while positioned in cannula 12. Similarly, whenguide wire. 11 is positioned in aperture 23, cannula 12 is movablerelative to guide wire 11. In this preferred embodiment, the diameter ofaperture 23 is decreased in distal end portion 16 by a taper of theinner surface of tubular wall 22 that decreases aperture 23 to thereduced second diameter at opening 25 in face 17. Tamping face 17 isshown as annular with a surface that is flat and perpendicular to thelongitudinal axis-X. It is understood that tamping face 17 can have avariety of shapes depending upon the desired application oftamp-apparatus 10 to include, for example, convex, faceted, angled fromthe perpendicular to the longitudinal axis or combinations thereof tofurther improve the application of tamping face 17.

As shown in FIG. 4, bone tamp apparatus 10 in a second preferredembodiment includes a cannula 12 and a stylet 26. Cannula 12 and stylet26 are separate components that can be connected together to form asingle integrated assembly. Cannula 12 is shown in a first position forpenetration and/or passing through a body wall and into a portion of abody such as a joint and/or an anatomical cavity. Stylet 26 is a secondcannula and defines a central longitudinal axis-X′. Cannula 12 andstylet 26 are shown as being arcuate and defining an arcuatelongitudinal axis-X, but it is understood that cannula 12 and stylet 26can have a straight shape.

Referring now to FIGS. 4 and 5, in this preferred embodiment distal endportion 16 of cannula 12 defines a plurality of slots 28 that extend ina proximal direction from face 17 for a predetermined distance to aproximal terminal end. Slots 28 separate a plurality of cantileveredelements 30 in tubular wall 22 of distal end portion 16. Slots 28 can bein fluid communication with aperture 23 or include seals that precludefluid communication from the environment external to tubular wall 22 toaperture 23 in the first position of tamp apparatus 10. Slots 28 arepreferably aligned with the longitudinal axis-X. The proximal terminalends of slots 28 approximately define the proximal terminal ends ofelements 30. A notch 32 is defined in tubular wall 22 in proximity tothe proximal terminal end of each element 30. In the first position oftamp apparatus 10, elements 30 extend distally and are approximatelyaligned with the longitudinal axis-X.

Cannula 12 can include a first handle 34 and/or a second handle 35 thatcan assist in the manipulation of tamp apparatus 10 during surgicalprocedures. Handles 34 and 35 can also perform other functions such asassisting in the connecting of cannula 12 and stylet 26 into anintegrated assembly.

As shown in FIGS. 5 and 6, in this one preferred embodiment of tampapparatus 10 distal end portion 16 of cannula 12 has four longitudinallyaligned slots 28 that separate tubular wall 22 into four cantileveredelements 30. One of the four elements 30 is removed to show the innersurfaces of tubular wall 22 of the remaining three elements 30. Face orterminal end 17 defines second opening 25 and includes the distal endsof each element 30 that define the tamping surface for cannula 12.

Second opening 25 in face 17 has a diameter that is preferably less thanthe diameter of first opening 24 of aperture 23. In this preferredembodiment, the diameter of aperture 23 is narrowed by a distallydirected taper of the inner surface of tubular wall 22 that decreasesthe diameter of aperture 23 to a reduced second diameter at opening 25in face 17. This tapered decrease in the diameter of the inner surfaceof the tubular wall 22 of elements 30 advantageously provides anincrease in the tamping surface of face 17.

Tubular wall 22 includes a hinge 3 for the rotation of elements 30between the first position and a second position of tamp apparatus 10.In this preferred embodiment, hinge 31 is a flexible hinge positioned inproximity to the proximal terminal end of each element 30 and/or notch32. Tubular wall 22 has material characteristics that accommodate therotational movement of elements 30 between the first position and thesecond position of tamp apparatus 10. Hinge 31 can also be a mechanicaljoint and or have the configuration of a pivot, for example. Hinge 31 ispreferably biased to the first position of tamp apparatus 10.

Referring now to FIGS. 4, 5 and 7, stylet 26 is a second cannula thatincludes a central section 36, a distal end portion 38 and a proximalend portion 40. Distal end portion 38 has a terminal free end or face 42that is a tamping surface of stylet 26. Proximal end portion 40 has aterminal free end or base 44.

Stylet 26 has a tubular wall 46 that defines an aperture 48 that is influid communication with a first opening 50 defined in terminal end orbase 42 and a second opening 52 defined in terminal end or face 42.Tubular wall 46 is a fluid tight conduit between openings 50 and 52. Thediameter of aperture 48 is at least sufficient to define a passagewayfor guide wire 11 and/or the injection of bone material. Stylet 26 isapproximately rigid along the longitudinal axis in that it directlytransfers axially directed forces.

In this preferred embodiment aperture 23 has a diameter that issufficient to receive at least distal end portion 38 and central section36. Cannula 12 and stylet 26 preferably have corresponding arcuateshaped distal end portions 16, 38 and central sections 14, 36,respectively such that when stylet 26 axis-X′ is approximately alignedwith cannula axis-X, aperture 23 of cannula 12 can receive at leastdistal end portion 38 and central section 36 of stylet 26 through firstopening 24.

Distal end portion 38 and face 42 of stylet 26 can vary in geometrydepending upon the desired application of tamp apparatus 10. Proximalend portion 40 of stylet 26 includes first opening 50 that can alsodefine a standard interface such as leer lock, for example, for use withadditional surgical instruments such as a syringe.

Referring now to FIG. 8, in one preferred embodiment of stylet 26,distal end portion 38 the outside diameter of tubular wall 46 has adistally increasing taper. The central section 36 of tubular wall 46 hasa first outside diameter and distal end portion 38 of tubular wall 46has a second outside diameter that is greater than the first outsidediameter. The taper of distal end portion 38 increases the outsidediameter of tubular wall 46 and preferably reaches a maximum diameter inproximity to face 42.

Referring now to FIG. 9, distal end portion 38 of stylet 26 has moveddistally into direct contact with the tapered inner surfaces of elements30 of tubular wall 22 that decrease the diameter of aperture 23. In thispreferred embodiment, distal end portion 38 of stylet 26 has a taperthat increases the outside diameter of tubular wall 46 in the distaldirection. Elements 30 are in the first position prior to deploying.Notches 32 are defined in tubular wall 22.

As shown in FIGS. 10 and 11, as stylet 26 continues to move in thedistal direction, distal end portion 38 deploys elements 30 bydisplacing elements 30 from the first position aligned with thelongitudinal axis-X to a second or deployed position of tamp apparatus10 wherein elements 30 are positioned at an oblique angle to thelongitudinal axis-X. Oblique as defined herein is transverse to orangled from the longitudinal axis and can include the angleperpendicular to the longitudinal axis. In this preferred embodiment,elements 30 rotate about their respective flexible hinges 31 in anoutward direction away from the longitudinal axis-X. In the secondposition of tamp apparatus 10, elements 30 are preferably flexiblyrotated to angle that is between greater than zero degrees andapproximately 30 degrees from the first position.

In the second position of tamp apparatus 10, elements 30 have completedtheir deployment and the surfaces of terminal end 42 and terminal end 17define a combined contiguous tamping surface of tamping apparatus 10. Inthis one preferred embodiment, in the second position terminal end 42 isapproximately flush or even with terminal end 17 to form an annulartamping face that is approximately a plane perpendicular to thelongitudinal axis. It is understood, however, that depending upon thedesired application of tamp apparatus 10, the tamping surface defined bythe combined terminal ends 42 and 17 can have a variety of shapes toinclude, for example, convex, faceted, angled from the perpendicular tothe longitudinal axis or combinations thereof to further improve theapplication of tamping face 17. The term tamping surface as definedherein is a surface or surface area that can include one or moreportions of cannula 12 and/or components, such as insert 9 and stylet26, of tamp apparatus 10 that have an at least partially distallydirected face and a structure suitable for use as a tamp.

The rotation of elements 30 between the first position and secondposition of tamp apparatus 10 can be assisted by stress relief devicessuch as, for example, notch 32, ribbing, and other means. In thispreferred embodiment, the flexible hinge 31 for each element 30 is inproximity to the notch 32 for that element 30. The inner side of tubularwall. 22 can also include stress relief devices that assist the rotationand/or bias of elements 30. Notch 32 is preferably radially aligned andis positioned in proximity to the proximal terminal end of each element30. Slots 28 can terminate in proximity to or extend proximal to notches32.

The rotational movement of elements 30 from the first position to thesecond position is limited by a retention mechanism. The retentionmechanism resists the rotation of flexible elements 30 from the firstposition to the second position by an external force, assists in theretaining of elements 30 in the deployed position and returns elements30 to approximately the first position from the second or deployedposition when the external force is removed. The retention mechanism canbe produced by the material characteristics of the tubular wall 22 ofelements 30 and/or, for example, a bias mechanism, such as a spring oran elastomer element that is integral to the hinge 31 of elements 30. Inthis preferred embodiment, the retention mechanism is a bias and/orresilience that is at least partially a result of the materialcharacteristics of elements 30 of tubular wall 22.

In the second position of tamp apparatus 10, the proximal end portion 40of stylet 26 and proximal end portion 18 of cannula 12 connect togetherto form a single integrated assembly. Proximal end portions 18 and 40are structured to receive and/or transfer a force applied approximatelyalong the aligned longitudinal axes-X and X′ to the combined tampingsurface of terminal ends 17 and 42.

As shown in FIG. 12, in one preferred embodiment of stylet 26 tubularwall 46 of distal end portion 38 has a uniform diameter, rather than ataper. This change of the shape of distal end portion 38 can also resultin a change of the tamping surface defined by terminal ends 17 and 42 oftamping apparatus 10 in the second position. Thus, the shape and size oftamping surface of tamp apparatus 10 can vary depending upon theintended application and includes factors such as the outside diameterof terminal end 17, diameter of opening 25, outside diameter of terminalend 42 and diameter of opening 52.

The changing of the shape of distal end portion 38 tubular wall 46between a uniform, distally decreasing or distally increasing outsidediameter selectively defines a desired combined tamping surface ofterminal end 17 and terminal end 42 for a particular application. As oneexample, terminal end 42 can have a first diameter, spread elements 30to a second diameter and define a first combined tamping surface ofterminal ends 17 and 42. Similarly, terminal end 42 can have a secondand larger diameter that spreads elements 30 to a third and largerdiameter and a second combined tamping surface of terminal ends 17 and42 that is larger than the first combined tamping surface. The tampingsurface of the combined terminal ends 17 and 42 can also take a varietyof shapes depending upon the desired application of tamp apparatus 10 asdescribed previously for terminal 17 of cannula 12.

As shown in FIGS. 13 and 15, bone tamp apparatus 10 in a third preferredembodiment includes a cannula 12, a first stylet 26A and a second stylet26B. Stylet 26A and 26B are separate components that can be selectivelypositioned into and removed from aperture 23 of cannula 12. Cannula 12and stylet 26A are shown in a first position for penetration and/orpassing through a body wall and into a portion of a body such as a jointand/or an anatomical cavity. Stylet 26A is a second cannula and definesa central longitudinal axis-X′ that is aligned with longitudinal axis-Xin the first position. Guide wire 11 can be selectively positioned inand removed from aperture 48 of stylet 26A.

In this preferred embodiment of tamp apparatus 10, distal end portion 16of cannula 12 and distal end portion 38 of stylet 26A approximately forma truncated cone. Distal end portion 16 has an outside diameter that hasa distally directed decreasing taper. Distal end portion 16 definesopening 25 of aperture 23. In this first position of tamp apparatus 10,distal end portion 38 of stylet 26A extends beyond opening 25 in thedistal direction. Distal end portion 38 is also preferably a truncatedcone with an outside diameter that has a distally directed decreasingtaper. Terminal end 42 of stylet 26A defines second opening 52 ofaperture 48.

Distal end portion 16 of cannula 12 includes a plurality oflongitudinally aligned movable elements 30 that are separated by slots28. Slots 28 can be in fluid communication with aperture 23 or includeseals that preclude fluid communication from the environment external totubular wall 22 to aperture 23 in the first position of tamp apparatus10. The proximal terminal ends of slots 28 define the proximal terminalends of elements 30.

In the first position, elements 30 extend in a distal direction.Elements 30 can be aligned with or at least partially offset fromtubular wall 22. There are eight elements 30 in this one preferredembodiment, but it is understood that the number of elements can varydepending upon the intended application.

Referring now to FIGS. 13 and 14, two opposed elements 30 of the eightelements 30 in this preferred embodiment are shown. Elements 30 have anapproximate wedge shape with a distally directed decreasing taper.Elements 30 have six walls including a distal end 30A, an opposedproximal end 30B, an inner surface or tamping face 30C, an outer surface30D and two opposed sides 30E. Proximal ends 30B connect inner surfaces30C and outer surfaces 30D. Proximal ends 30B and tamping faces 30C arepreferably perpendicular. Tamping faces 30C are approximately alignedwith the longitudinal axis-X and defines a portion of aperture 23 in thefirst position and. Outer surface 30D has taper that at least partiallydefines the tapered distal end portion 16 of cannula 12. Tamping face30C has a distal edge and outer surface 30D has distal edge that are inproximity and connect to distal end 30A. Sides 30E preferably include ataper such that distal end 30A has a reduced width perpendicular to aradial axis from the longitudinal axis relative to the width of proximalend 30B.

Cannula 12 includes a plurality of pivotal connections 31 that coupleeach element 30 to tubular wall 22. In this preferred embodiment of tampapparatus 10, connection 31 is a mechanical hinge and elements 30 rotatebetween the first position wherein elements 30 extend distally and areapproximately aligned with the longitudinal axis-X and a secondposition. Connection 31 preferably connects the portions of elements 30in proximity to the junction of proximal end 30B and outer surface 30Dto tubular wall 22.

Stylet 26A includes center section 36 that is coupled to distal endportion 38 and proximal end portion 40. Distal end portion 38 includes aplurality of notches or cutouts 43. In this preferred embodiment, thereare eight notches 43 and stylet 26A is aligned with cannula 12 such thateach notch 43 receives at least a portion of an element 30. Aperture 48has a diameter that receives the desired diameter of guide wire 11 for agiven application of tamp apparatus 10.

Cannula 12 includes a retention mechanism that assists in the retainingof each element 30 in the first position. The retention mechanism caninclude, for example, a bias member such as a spring that urges elements30 to the first position. Tubular wall 22 can also include, for example,a mechanical catch that retains elements 30 in the first position untila predetermined amount of force from an external source is exceeded.Similarly, a close fitting relationship between elements 30 and stylet26A can, retain elements 30 in the first position and/or preclude anyundesirable rotation of elements 30 about connections 31. Still further,each notch 43 can have a bias mechanism or shape that retains elements30 in the first position such as a flexible distal lip.

Distal ends 30A of elements 30 define second opening 25 of aperture 23.In this preferred embodiment, second opening 25 has a diameter that isless than the diameter of first opening 24 in proximal terminal end 19.Aperture 23 is decreased by inner surfaces 30C of elements 30 thatextend inside of the inner surface of tubular wall 22. The taper ofouter surfaces 30D are approximately aligned with the taper of distalend portion 38 of first stylet 26A. It is understood that while distalend portion 16 of cannula 12 and distal end portion 38 of stylet 26Aapproximately have an approximately truncated cone shape, these twocomponents can define alternative shapes in the first position dependingupon the intended application such as for example, ogive, angular orplanar.

Continuing with the third embodiment as shown in FIGS. 13 and 15, stylet26A has been removed from aperture 23 and stylet 26B is positioned inaperture 23 of cannula 12. The second position of tamp apparatus 10 isdefined by stylet 26B being fully positioned aperture 23 and connectedto cannula 12 to form an integrated assembly. Stylet 26B defines acentral longitudinal axis-X″. Aperture 48 of stylet 26B is aligned withthe longitudinal axis-X″. Tamping faces 30C of elements 30 and terminalend 42 of stylet 26B define the tamping surface of tamp apparatus 10.Cannula 12, stylet 26A and stylet 26B are shown as straight and definingstraight longitudinal axes-X, X′ and X″, but it is understood thatcannula 12, stylet 26A and stylet 26B can have arcuate shapes.

Referring now to FIGS. 15 and 16 stylet 26B is a third cannula thatincludes center section 36 that is coupled to distal end portion 38 andproximal end portion 40. Distal end portion 38 has a terminal end ortamping face 42 that is approximately perpendicular to the longitudinalaxes X and X″. Proximal end portion 40 includes proximal terminal end orbase 44 that is suitable for driving tamp apparatus 10.

Stylet 26B tubular wall 46 defines aperture 48 that is in fluidcommunication with a first opening 50 defined in terminal end or base 44and a second opening 52 defined in terminal end or face 42. Tubular wall46 is a fluid tight conduit between openings 50 and 52 for the injectionof bone graft. First opening 50 of stylet 26 can also define a standardinterface such as leur lock, for example, for use with additionalsurgical instruments such as a syringe. Stylet 26B is approximatelyrigid along the longitudinal axis in that it directly transfers axiallydirected forces.

As stylet 26B is inserted into opening 24 of aperture 23 of cannula 12,distal end portion 38 of stylet 268 is placed into contact with elements30. When tamp apparatus 10 is in the second position, distal end portion38 has rotated elements 30 about connections 31 from the first positionwherein elements 30 are approximately distally aligned to the secondposition wherein elements 30 are approximately perpendicular to thelongitudinal axes X and X″.

In this preferred embodiment, the portions of proximal ends 30B thatextend below the inner surface of tubular wall 22 are directly contactedby tamping face 42 as stylet 26B moves distally. As stylet 26B continuesdistally, elements 30 rotate about connections 31 and deploy to thesecond position. In the first position of tamp apparatus 10 proximalends 30B are approximately perpendicular to and tamping faces 30C areapproximately aligned with the longitudinal axis. In the secondposition, elements 30 have rotated about hinges 31 approximately ninetydegrees, proximal ends 30B are approximately aligned with thelongitudinal axis and tamping faces 30C are approximately perpendicularto the longitudinal axes and directed distally. The distally directedmovement of stylet 26B overcomes the force of the retention mechanismthat biases elements 30 to the first position. The outer surface oftubular wall 46 of stylet 26B is in direct contact with and fixes theproximal ends 30B of element 30 in the second position. Distal endportion 16 of cannula 12 can also include a stop 78 that limits therotational movement of elements 30 to the second position. Stop 78 ispreferably connected to tubular wall 22 and can further assist in theretaining of elements 30 in the second position.

As shown in FIGS. 16 and 17, in the second position of tamp apparatus10, terminal end 42 of stylet 26B and tamping faces 30C of elements 30define the combined contiguous tamping surface of tamping apparatus 10.In this one preferred embodiment, in the second position terminal end 42is approximately flush or even with inner surface 30C to form an annulartamping face that is approximately a plane perpendicular to thelongitudinal axis. It is understood that depending upon the desiredapplication of tamp apparatus 10, the tamping surface defined by thecombined terminal end portion 42 and tamping face 30C can have a varietyof two-dimensional and three-dimensional shapes to include, for example,convex, faceted, angled from the perpendicular to the longitudinal axisor combinations thereof.

Tamping faces 30C of the eight elements 30 in this preferred embodimentcan also take a variety of shapes to facilitate particular applicationsof tamp apparatus 10 in the second position. The varying of the shapesincludes the amount of taper, if any of sides 30E, the length of tampingface 30C in the radial direction from the longitudinal axis and widthperpendicular to the radial direction of tamping face 30C. Opening 52 isthe distal terminal end of aperture 23.

As shown in FIG. 18 in a fourth preferred embodiment of tamp apparatus10, cannula 12 includes central section 14, distal end portion 16, andproximal end portion 18 that define central longitudinal axis-X. Stylet26 in this embodiment is concentrically mounted and slidably securedwithin aperture 23 of tubular portion 14 in an adjoined close fittingrelationship. Terminal end 17 has an annular shape that defines opening25 of aperture 23. Terminal end 17 is fixed relative to tubular wall 22and stylet tamping face 42. Cannula 12 and stylet 26 are shown as beingstraight, but can also have an arcuate shape. Tamp apparatus 10 is shownin the first position.

In this preferred embodiment, cannula 12 defines a plurality oflongitudinally aligned slots 28 that separate a plurality of elements30. Slots 28 can be in fluid communication with aperture 23 or includeseals that preclude fluid communication from the environment external totubular wall 22 to aperture 23 in the first position of tamp apparatus10. The proximal and distal terminal ends of slots 28 approximatelydefine the proximal and distal terminal ends of elements 30. Eachelement 30 includes a plurality of hinges 31. Tubular wall 22 preferablyincludes devices for stress relief that are positioned in proximity toeach of the hinges 31 of elements 30.

In this one preferred embodiment of tamp apparatus 10 distal end portion16 has four longitudinally aligned slots 28 that separate tubular wall22 into four elements 30. Each element 30 has three hinges 31. A firstor distal hinge 31A is in proximity to a first notch 56, a second hinge31B is in proximity to a second notch 58 and a third hinge 31C is inproximity to a third notch 60. A distal first member 62 of each element30 extends between the first notch 56 and the second notch 58. Aproximal second member 64 of each element 30 extends between secondnotch 58 and third notch 60. In this preferred embodiment, the hinges31A, 31B and 31C of elements 30 are flexible hinges in tubular wall 22that are in proximity to each of notches 56, 58 and 60. Notches 56, 58and 60 provide stress relief, as described previously, that aid elements30 in rotating about their respective hinges 31A-C.

In this preferred embodiment, the hinges 31 are preferably flexiblehinges and tubular wall 22 has material characteristics that accommodatethe rotational movement of elements 30 between the first position andthe second position of tamp apparatus 10. The hinge 31 can also be amechanical joint and/or have the configuration of a pivot, for example.As shown in FIGS. 18 and 19, stylet 26 includes central section 36,distal end portion 38 and proximal end portion 40 that are aligned withcentral longitudinal axis-X. Stylet 26 has a tubular wall 46 that is afluid tight conduit that defines an aperture 48. Aperture 48 extendsbetween opening 50 defined in proximal end portion 40 and opening 52defined in terminal end or tamping face 42. Aperture 48 is preferablyaligned with the longitudinal axis-X.

The distal end portions 16 and 38 of cannula 12 and stylet 26are-connected together in proximity to terminal ends 17 and 42. Theconnection of terminal ends 17 and 42 is preferably by a snap-fitdetent, such that cannula 12 and stylet 26 can be readily assembled anddisassembled. It is understood, however, that the connection of terminalends 17 and 42 can be by any conventional technique to include a spotweld, a heat bond, an adhesive and/or any type of mechanical connectionsuch as threaded interface.

Proximal end portion 18 in this preferred embodiment includes a housing53 that defines a proximal stop 66 and a distal stop 68. Proximal endportion 40 of stylet 26 extends into housing 53. Base 44 of stylet 26 isset apart a predetermined distance within housing 53 from base 19 ofcannula 12 in the first position of tamp apparatus 10.

Base 19 of proximal end portion 18 is a wall that defines the proximalopening 25 to the interior of housing 53 and aperture 23. Opening 25provides access to base 44 and opening 50 of stylet 26. Opening 50 caninclude a standard interface such as a leur lock, for example, for usewith a syringe or additional surgical instruments. Base 44 can alsoinclude a handle 70 that extends proximal to housing 53. The leur lockand/or handle 70 can be used to grasp base 44 and pull stylet 26proximally relative to cannula 12 thereby deploying flexible elements30.

Proximal end portion 40 of stylet 26 includes a protuberance or ridge 72that extends radially outward from tubular wall 46 in proximity to base44. Ridge 72 is preferably a radially aligned annular wall. Ridge 72abuts distal stop 68 in the first position of tamp apparatus 10. Tampapparatus 10 also includes a lock 74 that fixes the relative positionsof cannula 12 and stylet 26 in the second position.

Referring now to FIGS. 19-21, tamp apparatus 10 moves from the first,position to the second position by the distal displacement of cannula 12along the longitudinal axis-X relative to stylet 26. In this preferredembodiment, the movement of tamp apparatus 10 from the first position tothe second position includes the deploying and rotating of first members62 and second members 64 of elements 30 about their respective hinges31A, 31B and 31C. Proximal end portion 40 of stylet 26 is displacedproximally relative to housing 53 of cannula 12. In the second position,the outer surfaces of first members 62 define a distally directedtamping face that is an additional portion of the tamping surface oftamping apparatus 10.

In the second position, the tamping face of first members 62 is combinedwith the tamping surfaces of terminal end 42 of stylet 26 and terminalend 17 of cannula 12 to define the combined tamping surface of tampapparatus 10. Tamp apparatus 10 can be constructed such that firstmembers 62 can deploy from an angle greater than zero degrees to anoblique angle that is at least slightly greater than ninety degrees toform an approximately concave tamping surface. Elements 30 arefabricated of materials and have tubular wall thicknesses that define astructure in the second position that can function as a bone tamp. Theangled positions of second members 64 provide structural support for theoblique angles of first members 62.

In the second position of tamp apparatus 10, proximal end portion 40 isdisplaced proximally relative to and within housing 53. The relativeproximal displacement of proximal end portion 40 in this preferredembodiment is halted by ridge 72 abutting proximal stop 66 of proximalend portion 18. In this preferred embodiment, housing 53 includes lock74 that secures ridge 72 abutting proximal stop 66. Lock 74 prevents thedistal movement of stylet 26 relative to cannula 12 in the secondposition that could undesirably return tamp apparatus 10 to the firstposition. Proximal end portion 18 preferably includes a releasemechanism such as a switch that deactivates lock 74 and allows thereturn of stylet 26 to the first position of tamp apparatus 10.

In this embodiment, lock 74 can further include fixing the relativepositions of cannula 12 and stylet 26 in multiple intermediate positionsbetween the first position and second position of tamp apparatus 10.Lock 74 can include elements well known in the art such as multipleengaging teeth or protuberances and insets, for example that can beengaged, locked and released from each position. These intermediatepositions can selectively vary the angular deployment of elements 30 andthereby alter the shape of the tamping surface during operational use.

As shown in FIGS. 2-3 and 22-23, the first embodiment of tamp apparatus10 in operation shows the distal end 13 of guide wire 11 beingintroduced through a pre-existing incision in a leg and positioned at apoint directly beneath a depressed fragment of bone or fracture of thetibial plateau. Tamp apparatus 10 is slid over the pre-positioned guidewire 11, through the incision and is positioned directly beneath thedepressed fragment of bone. Guide wire 11 can be further used to aligntamp apparatus 10 relative to the fracture.

Referring now to FIGS. 2-3 and 24, guide wire 11 is then withdrawnleaving tamp apparatus 10 in position for treating the fracture. Tampingface 17 of distal end portion 16 is in direct contact with the bone thatis to be displaced, central section 16 extends through the incision andproximal end portion 18 is clear of the patient. Mallet 8 is preferablyused to strike base 19 and drive tamping face 17, the tamping surface,into the tibia to displace and the return the depressed portion of thebone to a natural position. Insert 9 can be selectively employed to withcannula 12 to augment the tamping surface of tamp apparatus 10. Theoperational employment of insert 9 in aperture 23 can be especiallyadvantageous to any of the embodiments herein when a larger diameteraperture 23 (or aperture 48, see FIG. 7) is required. A larger diameteraperture 23 can be required, for example, when bone chips are added toor included in the bone graft or a more viscous bone graft is employed.The increased size of aperture 23 can result in a narrowing of tampingface 17 of cannula 12 that can be compensated by the selectiveemployment of insert 9.

As shown in FIG. 25, once the displacing of the fracture is completedinsert 9 is removed as required and a source of bone graft 76 isconnected to first opening 24 of cannula 12. The bone graft is suppliedunder pressure through aperture 23 to second opening 25. First opening24 defines an interface that is suitable for connecting with theexternal source of bone graft 76.

As the bone graft is injected from second opening 25 into the bone void,cannula 12 can be gradually withdrawn. The filling of the void by thebone graft and the withdrawal of the cannula can then be repeated untilthe bone void is completely filled with bone graft. This processadvantageously prevents the accumulation of blood and fatty bone marrowin the bone void which can occur when the tamp is removed prior to theplacement of the bone grail When blood and fatty bone marrow is allowedto fill the bone void during this procedure, the integration of the bonegraft with the native bone can be compromised.

After the bone void is tilled, terminal end 17 can be used to tamp thegraft in position. This can be done sequentially after each injectionand gradual withdrawal as well as after the bone graft injecting iscompleted. Alternatively, cannula 12 can inject bone graft continuouslyinto the bone void as tamp apparatus 10 is withdrawn. Insert 9 can beemployed as desired once bone graft injection is completed. The tampingof the bone graft can help to ensure that any voids left during theinjection are filled and the bone graft is condensed within the tibia.When the injection and tamping of the bone graft is completed, cannula12 is withdrawn,from the incision.

Tamp apparatus 10 in this and any of the embodiments can have an arcuateor straight shape depending upon the desired application. The arcuateshape has the advantage that the directional thrust of terminal end 17can be oriented to displace the depressed bone fragment at an angle thathas a closer alignment to the direction of the fracture in the tibialplateau. The straight tamp apparatus 10 can compensate for this byhaving a tamping face that has a specialized shape.

Referring now to FIGS. 4-12 and 22-26, the second embodiment of tampapparatus 10 in operation is initially the same as that for the firstembodiment. The distal end of guide wire 11 is introduced through anincision in a leg to a point directly beneath a depressed fragment ofbone or fracture of the tibial plateau. Cannula 12 is initially slidover the pre-positioned guide wire 11, through the incision and ispositioned directly beneath the depressed fragment of bone. Stylet 26 isslid over guide wire 11 and central section 36 and distal end portion 38are inserted through second opening 25 and into aperture 23. Guide wire11 can be timber used to align tamp apparatus 10 relative to thefracture.

Once tamp apparatus 10 is aligned with the fracture, tamping face 42 ofstylet 26 is moved through the distal end of aperture 23 and elements 30are displaced our deployed from the first position to the secondposition of tamp apparatus 10. In the second position elements 30 havebeen rotated about flexible hinges 31 and are deployed to apredetermined angle oblique to the longitudinal axis-X. The tampingsurface of tamp apparatus 10 in this second embodiment combines theapproximately aligned surfaces of terminal end 42 and terminal end 17.The proximal end portion 40 of stylet 26 and proximal end portion 18 ofcannula 12 are connected together as a single assembly. Guide wire 11 isremoved from the procedure through aperture 48.

With tamp apparatus 10 in the second position and aligned with thefracture, mallet 8 is preferably used to strike or tap base 44 and/orproximal end portion 40 of stylet 26. The combined tamping surface ofterminal ends 17 and 42 is driven into the tibia to displace and returnthe depressed portion of the bone to a natural position. The expandedtamping surface tamp apparatus 10 in the second embodimentadvantageously decreases the stress placed on the fracture fragmentsduring tamping and allows for minimal bone window and incision size. Itis understood that tamp apparatus 10 can include one or more stylet 26and that multiple stylet 26 can be selectively employed during a singlesurgical procedure to change the amount or the shape of the combinedtamping surface.

Once the displacing of the fracture is completed, a source of bone graft76 is connected to first opening 50 of stylet 26 and is supplied underpressure through aperture 46 to second opening 52. The pressure fromsource of bone graft 76 is sufficient to displace any bone material thathas penetrated into aperture 23 during tamping. The bone graft isinjected from opening 52 into the bone void as tamp apparatus 10 iswithdrawn. The filling of the void by the bone graft and the withdrawalof tamp apparatus 10 can then be repeated until the bone void iscompletely filled with bone graft. Alternatively, stylet 26 can injectbone graft continuously into the bone void as tamp apparatus 10 isgradually withdrawn.

After the injecting of the bone graft is completed, the combined tampingsurface of terminal ends 17 and 42 can be used to tamp the bone graft inposition as described above. When the tamping is completed, stylet 26 iswithdrawn from aperture 23 and the elements 30 of cannula 12 return toapproximately the first position by the retention mechanism of cannula12 and/or the interface with stylet 26. With elements 30 in the firstposition, cannula 12 is withdrawn from the incision.

Referring now to FIGS. 13-17, 27 and 28, the third embodiment of tampapparatus 10 in operation includes the introduction of the distal end ofguide wire 11 as described previously. Cannula 12 and stylet 26A in thefirst position are slid over the pre-positioned guide wire 11 and usedto approach the depressed fragment of bone. Stylet 26A is then withdrawnfrom the patient.

Stylet 26B is slid over the pre-positioned guide wire 11 and insertedthrough opening 24 of aperture 23 of cannula 12 and distal end portion38 of stylet 26B deploys elements 30 about connections 31 from the firstposition wherein elements 30 are approximately distally aligned to thesecond position wherein elements 30 are preferably perpendicular to thelongitudinal axis.

In this preferred embodiment, the portions of proximal ends 30.B thatextend below the inner surface of tubular wall 22 are contacted by face42 of stylet 26B and rotated about connections or hinges 31 as face 42moves distally displacing proximal end 30B to a position that isapproximately aligned with the longitudinal axis. Inner surface ortamping face 30C is then directed distally and fixed in position todefine the second position of tamp apparatus 10. The tamping surface oftamp apparatus 10 in the second position includes the distally directedtamping faces 30C and stylet 26B distal terminal end 42. As a result ofthe right angle relationship between proximal end 30B and tamping face30C in this preferred embodiment, the deployment of elements 30 to thesecond position of tamp apparatus 10 by stylet 26B rotates elements 30approximately 90 degrees.

In the second position of tamp apparatus 10, the proximal end portion 40of stylet 26B and proximal end portion 18 of cannula 12 preferablyconnect together to form a single integrated assembly. Proximal endportions 18 and 40 are structured to receive and/or transfer a forceapplied approximately along the aligned longitudinal axes-X and X′ tothe combined tamping surface of tamp apparatus 10.

Once tamp apparatus 10 is aligned with the fracture, guide wire 11 iswithdrawn from cannula 12 and stylet 26B. The integrated cannula 12 andstylet 26B are held in position and mallet 8 is used to strike or tapbase 44 (See FIG. 24). The combined tamping surface of terminal end 42and tamping faces 30C is driven into the tibia to displace and correctthe fracture to a natural position. Once the tamping of the fracture ofthe tibial plateau is completed, bone graft is injected into the bonevoid as described previously through aperture 48 of stylet 26B. The bonegraft fills the bone void and tamping apparatus 10 is returned to thefirst position by withdrawing stylet 26B from cannula 12. As required,first stylet 26A can be reinserted into aperture 23 of cannula 12.

As shown in FIGS. 18-25 and 29, the fourth embodiment of tamp apparatus10 in operation includes the introduction of the distal end of guidewire 11 as described previously. Cannula 12 and stylet 26 are anintegrated assembly that is slid over the pre-positioned guide wire 11and positioned directly beneath the depressed fragment of bone. Stylet26 is moved in aperture 23 relative to cannula 12 to reposition elements30 from the first position to the second position of tamp apparatus 10.One process for doing this includes holding onto proximal end portion 18of cannula 12 and displacing stylet 26 proximally in aperture 23 usingan instrument attached to the leur lock of aperture 50 of base 44 and/orhandle 70.

As cannula 12 advances distally relative to stylet 26 along thelongitudinal axis-X, the connection at terminal ends 42 and 1,7 forcethe hinges 31 of elements 30 to rotate. As cannula 12 moves relative tostylet 26, lock 74 of cannula 12 is displaced by ridge 72 of stylet 26.Once ridge 72 has passed lock 74 and tamp apparatus 10 is in the secondposition, lock 74 returns to the extended or locked position andsecures-cannula 12 in position relative to Stylet 26 in the secondposition of tamp apparatus 10. Ridge 72 is fixed in position betweenlock 74 and proximal stop 66 in housing 53. This position locks theangular relationship or second member 64 and first member 62 of cannula12 in a fixed position with sufficient rigidity and structural integrityto perform bone-tamping procedures. Guide wire 11 is removed from theprocedure through aperture 48.

Once tamp apparatus 10 is aligned with the fracture, cannula 12 ispreferably held by proximal end portion 18 and mallet 8 is used tostrike or tap base 19. The combined tamping surface of terminal ends 17and 42 with distal first members 62 of elements 30 is driven into thetibia to displace and return the depressed portion of the bone to anatural position. Once the tamping of the fracture of the tibial plateauis completed, bone graft is injected into the bone void as describedpreviously. The bone graft fills the bone void and tamping apparatus 10is returned to the first position by releasing lock 74 and forcingstylet 26 distally relative to cannula 12. Tamp apparatus 10 is thenwithdrawn from the incision.

The expanded tamping surface of tamp apparatus 10 in the embodimentsherein advantageously decrease the stress placed on the fracturefragments during tamping and allow for minimal bone window and incisionsize. Aperture 23 and aperture 48 provide a passageway for guide wire 11that enables tamp apparatus 10 to be guided directly into the desiredposition and angle for tamping. In addition, aperture 48 provides theadvantage of a conduit that can supply, inject and tamp the injectedbone graft continuously into the bone void as tamp apparatus 10 iswithdrawn from the bone void.

Cannula 12 and stylet 26 (to include stylet 26A and 26B) can be made ofmaterials suitable for medical applications such as but not limited topolymers, composites and metals. Tamp apparatus 10 is preferably areusable assembly that can be disassembled as required and sterilized,but it can also be constructed as a disposable device. Cannula 12,stylet 26 and insert 9 are approximately incompressible along theirrespective longitudinal axes for their intended applications.

In the preceding specification, the present disclosure has beendescribed with reference to specific exemplary embodiments thereof. Itwill be evident, however, that various modifications, combinations andchanges may be made thereto without departing from the broader spiritand scope of the invention as set forth in the claims that follow. Forexample, while the tamp apparatus 10 is described herein is adapted foruse with insert 9 and guide wire 11, it is understood that the tampapparatus 10 can be selectively used without insert 9 and guide wire 11.In addition, though the present invention is described in terms of aseries of embodiments, each embodiment of the present invention cancombine one or more novel features of the other embodiments. Thespecification and drawings are accordingly to be regarded in anillustrative manner rather than a restrictive sense.

What is claimed is:
 1. A tamp apparatus for use in surgical operationsfor the realignment of fractured bone, the tamp apparatus comprises: acannula that has a tubular wall that includes a distal end portion and aproximal end portion, the distal end portion includes a distal terminalend and the proximal end portion includes a proximal terminal end; alumen defined by the tubular wall of the cannula, the lumen extends froma first opening defined in the proximal terminal end to a second openingdefined in the distal terminal end, the first opening optionally adaptedto couple with a source of bone graft material and the second openingoptionally adapted for the injecting of bone graft material; a distallydirected tamping face of the cannula adapted for the displacement ofbone from a fractured position to an approximately natural position, thetamping face defined by the distal terminal end of the distal endportion of the cannula between an outside diameter of the tubular wallof distal terminal end and an outside diameter of the second opening; acentral longitudinal axis defined between the distal end portion and theproximal end portion of the cannula, the distal end portion includes aplurality of slots defined in the tubular wall and the slots define aplurality of elements, each element includes a distally directed taperof the inner surface of the cannula tubular wall that decreases thediameter of the cannula second opening, the elements movable between afirst position wherein the elements are approximately aligned with thelongitudinal axis and a second position wherein the elements are obliqueto the longitudinal axis, the slots extend from the distal terminal endproximally to a terminal end of the slot, the tamping face of thecannula includes a distal end of each element, the tubular wall includesa hinge in proximity to the terminal end of the slot for the movement ofeach element between the first position and the second position, theelements in the second position rotatingly moved outward from thecentral longitudinal axis about the hinge, the elements including aretention mechanism, the retention mechanism resists the rotation of theelements from the first position to the second position and biases theelements to the first position; and a stylet that includes a distal endportion and a proximal end portion, the stylet distal end portionincludes a distally directed end that defines a stylet tamping face, thestylet approximately axially rigid, the stylet movable in the lumen ofthe cannula to contact the distally directed tapered inner surface ofthe cannula tubular wall and move the elements from the first positionto the second position, the cannula and stylet of the tamp apparatusfixed in the second position, a tamping face of the tamp apparatus inthe second position defined by the distal ends of the elements of thecannula and distal end of the stylet.
 2. The tamp apparatus of claim 1,wherein in the first position the cannula first opening has a firstdiameter and the cannula second opening has a second diameter, in thefirst position the diameter of the cannula first opening is larger thanthe diameter of the cannula second opening, the cannula tubular wallincludes a tapered inner surface that decreases to the diameter of thesecond opening and increases the surface of the cannula tamping face. 3.The tamp apparatus of claim 1, wherein the stylet defines an aperturethat extends between a proximal opening in the proximal end portion anda distal opening in the distal end portion of the stylet, the proximalopening of the aperture of the stylet is adapted to connect to anexternal source of bone graft material and the stylet is, adapted toinject the bone graft material under pressure from the distal opening ofthe aperture.
 4. The tamp apparatus of claim 1, wherein the styletprovides a displacing force to the distally directed taper of theelements, to move the elements between the first position and the secondposition, the tamping face of the tamp apparatus includes the distal endof the stylet and distal ends of the elements in the second positionfixed in approximate alignment.
 5. The tamp apparatus of claim 1,wherein the elements are returned from the second position toapproximately the first position by the retention mechanism andwithdrawal of the stylet interface with the distally directed taper ofthe elements.
 6. The tamp apparatus of claim 1 that further includes aguide wire.
 7. The tamp apparatus of claim 1, wherein the proximal endportions of the stylet and cannula connect together and are structuredto receive and transfer force along the longitudinal axis to thecombined tamping face of the terminal ends of the cannula and stylet. 8.The tamp apparatus of claim 1, wherein the stylet includes at least twocylindrical shaped stylets with different distal end shapes, the styletsselectable to define a desired shape of a surface of the tamping face inthe second position.
 9. The tamp apparatus of claim 1, wherein the tampapparatus includes a proximal end portion and the proximal end portionincludes a base, the cannula and stylet fixed in the second position andthe base adapted to receive an external force and transfer the externalforce from the base to the tamping face of tamp apparatus.
 10. The tampapparatus of claim 1, wherein the stylet includes at least two styletswith distal end portions that include tubular walls of differingdiameters and the diameter of the distal end portion of each stylet isselected to define a desired combined diameter of tamping face of thestylet and cannula in the second position.
 11. The tamp apparatus ofclaim 1, wherein the tamp apparatus in the second position is adapted todisplace at least cancellous bone.
 12. A method of treating a bonefracture using a tamp apparatus comprising the steps of: introducing aguide wire through a hole cut in a cortex of a bone and positioning adistal end of the guide wire in proximity to a bone fracture; coupling alongitudinally aligned lumen of a cannula of the tamp apparatus to theguide wire and positioning a distally directed tamping face of thecannula of the tamp apparatus for treating the bone fracture, the tampapparatus further including a stylet with a distal end tamping face;inserting the stylet into the lumen and connecting the stylet andcannula of the tamp apparatus into an integrated tamp apparatusassembly, the tamp apparatus includes a distal end of the cannuladefining a plurality of movable elements that are longitudinally alignedin a first position with a central longitudinal axis defined by thecannula and the plurality of elements biased to the first position, theinserting of the stylet in the lumen deploying the elements outward fromthe first position of longitudinal alignment to a second positionoblique to the longitudinal axis, the second position includes theapproximate alignment of the distal end of the stylet and distal ends ofthe elements, the second position fixing the positions of the stylet andcannula, the combined stylet and cannula tamp apparatus in the secondposition increasing the area of a tamping face of the tamp apparatus;treating the bone fracture by striking a proximal end of the tampapparatus and using the tamping face of the tamp apparatus to displaceand return the fractured bone to an approximately natural position. 13.The method of treating a bone fracture of claim 12 further comprisingthe step of removing the guide wire from the tamp apparatus when thetamp apparatus is positioned for treating the fracture.
 14. The methodof treating a bone fracture of claim 12 further comprising the step ofselectively positioning the elements of the tamp apparatus from thefirst position with a first tamping face surface area and first diameterof the cannula and the second position with a second tamping facesurface area that includes the combined distal ends of the cannula andstylet, the second tamping face surface area and diameter being greaterthan the first tamping face surface area and diameter.
 15. The method oftreating a bone fracture of claim 12, wherein the stylet defines anaperture that extends between, a distal opening in a distal terminal endand a proximal opening in a proximal, terminal end of the stylet andfurther comprising the step of injecting bone graft material through thedistal opening of the lumen of the tamp apparatus, the bone graftmaterial filling the voids left by the corrective repositioning of thefractured bone and the withdrawal of, the tamp apparatus, the bone tampcondensing the bone graft material in the voids.
 16. The method oftreating a bone fracture using a tamp apparatus of claim 12, wherein thestep of treating the fracture includes treating cortical bone materialand cancellous bone material.
 17. A tamp apparatus for use in surgicaloperations for the realignment of fractured bone, the tamp apparatuscomprises: a cannula that has a tubular wall that includes a distal endportion and a proximal end portion, the distal end portion includes adistal terminal end and a the proximal end portion includes a proximalterminal end; a lumen defined by the tubular wall of the cannula, thelumen extends from a first opening defined in the proximal terminal endto a second opening defined in the distal terminal end, the firstopening can further include being adapted to couple with a source ofbone graft material and the second opening can further include beingconfigured for the injection of bone graft material, the first openinghas a first diameter and the second opening has a second diameter, thediameter of the first opening is larger than the diameter of the secondopening, the distal end portion of the cannula includes a distallydirected taper of the inner wall of the tubular wall that defines thelumen, the taper of the inner tubular wall decreases the diameter of thesecond opening; a distally directed tamping face of the cannula adaptedto displace bone from a fractured position to an approximately naturalposition, the tamping face defined by the distal terminal end of thedistal end portion of cannula between an outside diameter of the tubularwall of distal terminal end and an outside diameter of the secondopening, the distal taper of the inner surface of the tubular wallincreases the surface of the tamping face; a central longitudinal axisdefined between the distal end portion and the proximal end portion ofthe cannula, the distal end portion includes a plurality of slotsdefined in the tubular wall and the slots define a plurality ofelements, the elements movable between a first position wherein theelements are approximately aligned with the longitudinal axis and asecond position where in the elements are oblique to the longitudinalaxis, the slots extend from the distally directed tamping faceproximally to a terminal end, the tamping face including a distal end ofeach element, the tubular wall includes a hinge in proximity to theterminal end of the slot for the movement of each element between thefirst position and the second position, the element in the secondposition moved about the hinge and outward from the central longitudinalaxis; a retention mechanism that includes the elements resistingrotation from the first position to the second position and biases theelements to the first position; and a stylet that extends between adistal end portion and a proximal end portion, the proximal end portionof the stylet includes a base, the distal end portion of the styletincludes a tamping face, the stylet insertable into the lumen of thecannula, the stylet approximately axially rigid and movable in thelumen, the stylet adapted to contact and displace the tapered portion ofthe tubular wall of the cannula and move the elements from the firstposition to the second position, the cannula and stylet connect togetherin the second position as a fixed assembly for tamping, a tamping faceof the tamp apparatus defined by the distal ends of the elements in thesecond position and stylet distal end, the base adapted to receive anexternal force that drives the tamping faces of the stylet and elements.18. The tamp apparatus of claim 17, wherein the second position fixesthe relative positions of the cannula and the stylet, the secondposition structured to receive and transfer force along the longitudinalaxis to the combined tamping face of the terminal ends of the cannulaand stylet, in the second position the terminal ends of the cannula andthe stylet define a contiguous tamping face, in the second position theterminal ends of the cannula and stylet are approximately flush.
 19. Thetamp apparatus of claim 17, wherein the stylet includes a tubular wall,the tubular wall of the stylet defines a fluid tight conduit, the styletadapted to transfer bone graft material from an opening defined in theproximal end portion of the stylet to an opening defined in the distalend portion of the stylet.
 20. The tamp apparatus of claim 17, whereinthe retention mechanism assists in the retaining of the elements in thesecond position against the stylet.
 21. The tamp apparatus of claim 17,wherein the stylet includes at least two stylets with differingdiameters and the diameter of the stylet is selected to define a desireddiameter of combined tamping face of the stylet and cannula in thesecond position.
 22. The tamp apparatus of claim 17, wherein the stylethas a tubular wall and the tubular wall defines an aperture, the base ofthe stylet defines a proximal opening of the aperture that includes aconnector adapted to interface with an external source of bone graftmaterial and the distal end of the stylet defines a distal opening, thedistal opening of the stylet adapted to inject the bone graft material.23. The tamp apparatus of claim 17, wherein the tamp apparatus in thesecond position is adapted to displace cancellous bone and corticalbone.